diff --git a/flask_rest_jsonapi/api.py b/flask_rest_jsonapi/api.py
index 71d6199..93ee5ee 100644
--- a/flask_rest_jsonapi/api.py
+++ b/flask_rest_jsonapi/api.py
@@ -7,6 +7,7 @@
 import inspect
 from functools import wraps
 
+from flask import Flask
 from flask_rest_jsonapi.resource import ResourceList
 
 
@@ -20,12 +21,19 @@ def __init__(self, app=None, blueprint=None, decorators=None):
         :param blueprint: a flask blueprint
         :param tuple decorators: a tuple of decorators plugged to each resource methods
         """
+
+        if app is None:
+            app = Flask(__name__)
+
         self.app = app
         self.blueprint = blueprint
         self.resources = []
         self.resource_registry = []
         self.decorators = decorators or tuple()
 
+        self.app.config.setdefault('PAGE_SIZE', 30)
+
+
     def init_app(self, app=None, blueprint=None):
         """Update flask application with our api